Ping ...
With the [1/2]??
thanks,
Kinglong Mee
On 1/19/2017 16:37, Kinglong Mee wrote:
>
>
> Commit bb6aeba736ba "NFSv4.x: Switch to using svc_set_num_threads()
> to manage the callback threads" change nfs start/stop threads
> through svc_set_num_threads().
>
> It destroy old threads by SIGINT signal, but our nfs4_callback_svc()
> isn't interruptible. So that, the callback threads will never be killed.
>
> # mount -t nfs -overs=4.2 nfstestnic:/ /mnt/
> # ps -ajx |grep NFS
> 2 5927 0 0 ? -1 S 0 0:00 [NFSv4 callback]
> # umount /mnt
> # ps -ajx |grep NFS
> 2 5927 0 0 ? -1 S 0 0:00 [NFSv4 callback]
> # mount -t nfs -overs=4.2 nfstestnic:/ /mnt/
> # umount /mnt
> # ps -ajx |grep NFS
> 2 5927 0 0 ? -1 S 0 0:00 [NFSv4 callback]
> 2 5963 0 0 ? -1 S 0 0:00 [NFSv4 callback]
>
> After one mount, there will be one callback thread left that cannot killed,
> the same time, nfs.ko will never be unplugged.
>
> v2, drop the wrong setting of rqstp->rq_server = NULL
>
> Signed-off-by: Kinglong Mee <kinglongmee@xxxxxxxxx>
> ---
> fs/nfs/callback.c | 39 +++++++++++++++++++++++++++++++++++----
> 1 file changed, 35 insertions(+), 4 deletions(-)
>
> diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
> index 0a21150..2a0fffd 100644
> --- a/fs/nfs/callback.c
> +++ b/fs/nfs/callback.c
> @@ -73,6 +73,15 @@ nfs4_callback_svc(void *vrqstp)
> int err;
> struct svc_rqst *rqstp = vrqstp;
>
> + /*
> + * thread is spawned with all signals set to SIG_IGN, re-enable
> + * the ones that will bring down the thread
> + */
> + allow_signal(SIGKILL);
> + allow_signal(SIGHUP);
> + allow_signal(SIGINT);
> + allow_signal(SIGQUIT);
> +
> set_freezable();
>
> while (!kthread_should_stop()) {
> @@ -80,11 +89,18 @@ nfs4_callback_svc(void *vrqstp)
> * Listen for a request on the socket
> */
> err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
> - if (err == -EAGAIN || err == -EINTR)
> + if (err == -EAGAIN)
> continue;
> + else if (err == -EINTR)
> + break;
> svc_process(rqstp);
> }
> - return 0;
> +
> + flush_signals(current);
> +
> + /* Release the thread */
> + svc_exit_thread(rqstp);
> + module_put_and_exit(0);
> }
>
> #if defined(CONFIG_NFS_V4_1)
> @@ -100,6 +116,15 @@ nfs41_callback_svc(void *vrqstp)
> int error;
> DEFINE_WAIT(wq);
>
> + /*
> + * thread is spawned with all signals set to SIG_IGN, re-enable
> + * the ones that will bring down the thread
> + */
> + allow_signal(SIGKILL);
> + allow_signal(SIGHUP);
> + allow_signal(SIGINT);
> + allow_signal(SIGQUIT);
> +
> set_freezable();
>
> while (!kthread_should_stop()) {
> @@ -121,11 +146,17 @@ nfs41_callback_svc(void *vrqstp)
> } else {
> spin_unlock_bh(&serv->sv_cb_lock);
> schedule();
> + if (signalled())
> + break;
> finish_wait(&serv->sv_cb_waitq, &wq);
> }
> - flush_signals(current);
> }
> - return 0;
> +
> + flush_signals(current);
> +
> + /* Release the thread */
> + svc_exit_thread(rqstp);
> + module_put_and_exit(0);
> }
>
> static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
>
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